include/linux/cpufreq.h

   1 /*
   2  *  linux/include/linux/cpufreq.h
   3  *
   4  *  Copyright (C) 2001 Russell King
   5  *            (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11 #ifndef _LINUX_CPUFREQ_H
  12 #define _LINUX_CPUFREQ_H
  13
  14 #include <asm/cputime.h>
  15 #include <linux/mutex.h>
  16 #include <linux/notifier.h>
  17 #include <linux/threads.h>
  18 #include <linux/kobject.h>
  19 #include <linux/sysfs.h>
  20 #include <linux/completion.h>
  21 #include <linux/workqueue.h>
  22 #include <linux/cpumask.h>
  23 #include <asm/div64.h>
  24
  25 #define CPUFREQ_NAME_LEN 16
  26 /* Print length for names. Extra 1 space for accomodating '\n' in prints */
  27 #define CPUFREQ_NAME_PLEN (CPUFREQ_NAME_LEN + 1)
  28
  29
  30 /*********************************************************************
  31  *                     CPUFREQ NOTIFIER INTERFACE                    *
  32  *********************************************************************/
  33
  34 #define CPUFREQ_TRANSITION_NOTIFIER     (0)
  35 #define CPUFREQ_POLICY_NOTIFIER         (1)
  36
  37 #ifdef CONFIG_CPU_FREQ
  38 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
  39 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
  40 extern void disable_cpufreq(void);
  41 #else           /* CONFIG_CPU_FREQ */
  42 static inline int cpufreq_register_notifier(struct notifier_block *nb,
  43                                                 unsigned int list)
  44 {
  45         return 0;
  46 }
  47 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
  48                                                 unsigned int list)
  49 {
  50         return 0;
  51 }
  52 static inline void disable_cpufreq(void) { }
  53 #endif          /* CONFIG_CPU_FREQ */
  54
  55 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency
  56  * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
  57  * two generic policies are available:
  58  */
  59
  60 #define CPUFREQ_POLICY_POWERSAVE        (1)
  61 #define CPUFREQ_POLICY_PERFORMANCE      (2)
  62
  63 /* Frequency values here are CPU kHz so that hardware which doesn't run
  64  * with some frequencies can complain without having to guess what per
  65  * cent / per mille means.
  66  * Maximum transition latency is in nanoseconds - if it's unknown,
  67  * CPUFREQ_ETERNAL shall be used.
  68  */
  69
  70 struct cpufreq_governor;
  71
  72 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
  73 extern struct kobject *cpufreq_global_kobject;
  74
  75 #define CPUFREQ_ETERNAL                 (-1)
  76 struct cpufreq_cpuinfo {
  77         unsigned int            max_freq;
  78         unsigned int            min_freq;
  79
  80         /* in 10^(-9) s = nanoseconds */
  81         unsigned int            transition_latency;
  82 };
  83
  84 struct cpufreq_real_policy {
  85         unsigned int            min;    /* in kHz */
  86         unsigned int            max;    /* in kHz */
  87         unsigned int            policy; /* see above */
  88         struct cpufreq_governor *governor; /* see below */
  89 };
  90
  91 struct cpufreq_policy {
  92         cpumask_var_t           cpus;   /* CPUs requiring sw coordination */
  93         cpumask_var_t           related_cpus; /* CPUs with any coordination */
  94         unsigned int            shared_type; /* ANY or ALL affected CPUs
  95                                                 should set cpufreq */
  96         unsigned int            cpu;    /* cpu nr of registered CPU */
  97         struct cpufreq_cpuinfo  cpuinfo;/* see above */
  98
  99         unsigned int            min;    /* in kHz */
 100         unsigned int            max;    /* in kHz */
 101         unsigned int            cur;    /* in kHz, only needed if cpufreq
 102                                          * governors are used */
 103         unsigned int            policy; /* see above */
 104         struct cpufreq_governor *governor; /* see below */
 105
 106         struct work_struct      update; /* if update_policy() needs to be
 107                                          * called, but you're in IRQ context */
 108
 109         struct cpufreq_real_policy      user_policy;
 110
 111         struct kobject          kobj;
 112         struct completion       kobj_unregister;
 113 };
 114
 115 #define CPUFREQ_ADJUST          (0)
 116 #define CPUFREQ_INCOMPATIBLE    (1)
 117 #define CPUFREQ_NOTIFY          (2)
 118 #define CPUFREQ_START           (3)
 119
 120 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
 121 #define CPUFREQ_SHARED_TYPE_HW   (1) /* HW does needed coordination */
 122 #define CPUFREQ_SHARED_TYPE_ALL  (2) /* All dependent CPUs should set freq */
 123 #define CPUFREQ_SHARED_TYPE_ANY  (3) /* Freq can be set from any dependent CPU*/
 124
 125 /******************** cpufreq transition notifiers *******************/
 126
 127 #define CPUFREQ_PRECHANGE       (0)
 128 #define CPUFREQ_POSTCHANGE      (1)
 129 #define CPUFREQ_RESUMECHANGE    (8)
 130 #define CPUFREQ_SUSPENDCHANGE   (9)
 131
 132 struct cpufreq_freqs {
 133         unsigned int cpu;       /* cpu nr */
 134         unsigned int old;
 135         unsigned int new;
 136         u8 flags;               /* flags of cpufreq_driver, see below. */
 137 };
 138
 139
 140 /**
 141  * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
 142  * @old:   old value
 143  * @div:   divisor
 144  * @mult:  multiplier
 145  *
 146  *
 147  *    new = old * mult / div
 148  */
 149 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
 150 {
 151 #if BITS_PER_LONG == 32
 152
 153         u64 result = ((u64) old) * ((u64) mult);
 154         do_div(result, div);
 155         return (unsigned long) result;
 156
 157 #elif BITS_PER_LONG == 64
 158
 159         unsigned long result = old * ((u64) mult);
 160         result /= div;
 161         return result;
 162
 163 #endif
 164 };
 165
 166 /*********************************************************************
 167  *                          CPUFREQ GOVERNORS                        *
 168  *********************************************************************/
 169
 170 #define CPUFREQ_GOV_START  1
 171 #define CPUFREQ_GOV_STOP   2
 172 #define CPUFREQ_GOV_LIMITS 3
 173
 174 struct cpufreq_governor {
 175         char    name[CPUFREQ_NAME_LEN];
 176         int     (*governor)     (struct cpufreq_policy *policy,
 177                                  unsigned int event);
 178         ssize_t (*show_setspeed)        (struct cpufreq_policy *policy,
 179                                          char *buf);
 180         int     (*store_setspeed)       (struct cpufreq_policy *policy,
 181                                          unsigned int freq);
 182         unsigned int max_transition_latency; /* HW must be able to switch to
 183                         next freq faster than this value in nano secs or we
 184                         will fallback to performance governor */
 185         struct list_head        governor_list;
 186         struct module           *owner;
 187 };
 188
 189 /*
 190  * Pass a target to the cpufreq driver.
 191  */
 192 extern int cpufreq_driver_target(struct cpufreq_policy *policy,
 193                                  unsigned int target_freq,
 194                                  unsigned int relation);
 195 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
 196                                    unsigned int target_freq,
 197                                    unsigned int relation);
 198
 199
 200 extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
 201                                    unsigned int cpu);
 202
 203 int cpufreq_register_governor(struct cpufreq_governor *governor);
 204 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 205
 206
 207 /*********************************************************************
 208  *                      CPUFREQ DRIVER INTERFACE                     *
 209  *********************************************************************/
 210
 211 #define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
 212 #define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */
 213
 214 struct freq_attr;
 215
 216 struct cpufreq_driver {
 217         struct module           *owner;
 218         char                    name[CPUFREQ_NAME_LEN];
 219         u8                      flags;
 220
 221         /* needed by all drivers */
 222         int     (*init)         (struct cpufreq_policy *policy);
 223         int     (*verify)       (struct cpufreq_policy *policy);
 224
 225         /* define one out of two */
 226         int     (*setpolicy)    (struct cpufreq_policy *policy);
 227         int     (*target)       (struct cpufreq_policy *policy,
 228                                  unsigned int target_freq,
 229                                  unsigned int relation);
 230
 231         /* should be defined, if possible */
 232         unsigned int    (*get)  (unsigned int cpu);
 233
 234         /* optional */
 235         unsigned int (*getavg)  (struct cpufreq_policy *policy,
 236                                  unsigned int cpu);
 237         int     (*bios_limit)   (int cpu, unsigned int *limit);
 238
 239         int     (*exit)         (struct cpufreq_policy *policy);
 240         int     (*suspend)      (struct cpufreq_policy *policy);
 241         int     (*resume)       (struct cpufreq_policy *policy);
 242         struct freq_attr        **attr;
 243 };
 244
 245 /* flags */
 246
 247 #define CPUFREQ_STICKY          0x01    /* the driver isn't removed even if
 248                                          * all ->init() calls failed */
 249 #define CPUFREQ_CONST_LOOPS     0x02    /* loops_per_jiffy or other kernel
 250                                          * "constants" aren't affected by
 251                                          * frequency transitions */
 252 #define CPUFREQ_PM_NO_WARN      0x04    /* don't warn on suspend/resume speed
 253                                          * mismatches */
 254
 255 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 256 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 257
 258
 259 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
 260
 261
 262 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
 263 {
 264         if (policy->min < min)
 265                 policy->min = min;
 266         if (policy->max < min)
 267                 policy->max = min;
 268         if (policy->min > max)
 269                 policy->min = max;
 270         if (policy->max > max)
 271                 policy->max = max;
 272         if (policy->min > policy->max)
 273                 policy->min = policy->max;
 274         return;
 275 }
 276
 277 struct freq_attr {
 278         struct attribute attr;
 279         ssize_t (*show)(struct cpufreq_policy *, char *);
 280         ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
 281 };
 282
 283 #define cpufreq_freq_attr_ro(_name)             \
 284 static struct freq_attr _name =                 \
 285 __ATTR(_name, 0444, show_##_name, NULL)
 286
 287 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
 288 static struct freq_attr _name =                 \
 289 __ATTR(_name, _perm, show_##_name, NULL)
 290
 291 #define cpufreq_freq_attr_rw(_name)             \
 292 static struct freq_attr _name =                 \
 293 __ATTR(_name, 0644, show_##_name, store_##_name)
 294
 295 struct global_attr {
 296         struct attribute attr;
 297         ssize_t (*show)(struct kobject *kobj,
 298                         struct attribute *attr, char *buf);
 299         ssize_t (*store)(struct kobject *a, struct attribute *b,
 300                          const char *c, size_t count);
 301 };
 302
 303 #define define_one_global_ro(_name)             \
 304 static struct global_attr _name =               \
 305 __ATTR(_name, 0444, show_##_name, NULL)
 306
 307 #define define_one_global_rw(_name)             \
 308 static struct global_attr _name =               \
 309 __ATTR(_name, 0644, show_##_name, store_##_name)
 310
 311
 312 /*********************************************************************
 313  *                        CPUFREQ 2.6. INTERFACE                     *
 314  *********************************************************************/
 315 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 316 int cpufreq_update_policy(unsigned int cpu);
 317
 318 #ifdef CONFIG_CPU_FREQ
 319 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
 320 unsigned int cpufreq_get(unsigned int cpu);
 321 #else
 322 static inline unsigned int cpufreq_get(unsigned int cpu)
 323 {
 324         return 0;
 325 }
 326 #endif
 327
 328 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
 329 #ifdef CONFIG_CPU_FREQ
 330 unsigned int cpufreq_quick_get(unsigned int cpu);
 331 unsigned int cpufreq_quick_get_max(unsigned int cpu);
 332 #else
 333 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 334 {
 335         return 0;
 336 }
 337 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
 338 {
 339         return 0;
 340 }
 341 #endif
 342
 343
 344 /*********************************************************************
 345  *                       CPUFREQ DEFAULT GOVERNOR                    *
 346  *********************************************************************/
 347
 348
 349 /*
 350   Performance governor is fallback governor if any other gov failed to
 351   auto load due latency restrictions
 352 */
 353 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
 354 extern struct cpufreq_governor cpufreq_gov_performance;
 355 #endif
 356 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 357 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_performance)
 358 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
 359 extern struct cpufreq_governor cpufreq_gov_powersave;
 360 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_powersave)
 361 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 362 extern struct cpufreq_governor cpufreq_gov_userspace;
 363 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_userspace)
 364 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
 365 extern struct cpufreq_governor cpufreq_gov_ondemand;
 366 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_ondemand)
 367 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
 368 extern struct cpufreq_governor cpufreq_gov_conservative;
 369 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_conservative)
 370 #endif
 371
 372
 373 /*********************************************************************
 374  *                     FREQUENCY TABLE HELPERS                       *
 375  *********************************************************************/
 376
 377 #define CPUFREQ_ENTRY_INVALID ~0
 378 #define CPUFREQ_TABLE_END     ~1
 379
 380 struct cpufreq_frequency_table {
 381         unsigned int    index;     /* any */
 382         unsigned int    frequency; /* kHz - doesn't need to be in ascending
 383                                     * order */
 384 };
 385
 386 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 387                                     struct cpufreq_frequency_table *table);
 388
 389 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 390                                    struct cpufreq_frequency_table *table);
 391
 392 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 393                                    struct cpufreq_frequency_table *table,
 394                                    unsigned int target_freq,
 395                                    unsigned int relation,
 396                                    unsigned int *index);
 397
 398 /* the following 3 funtions are for cpufreq core use only */
 399 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 400 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 401 void   cpufreq_cpu_put(struct cpufreq_policy *data);
 402
 403 /* the following are really really optional */
 404 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 405
 406 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 407                                       unsigned int cpu);
 408
 409 void cpufreq_frequency_table_put_attr(unsigned int cpu);
 410 #endif /* _LINUX_CPUFREQ_H */